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A multiwavelength study of the IRAS Deep Survey galaxy sample III.
Spectral classification and dynamical properties: The infrared deep sample (IDS), in the north ecliptical polar region (NEPR),
is the first complete, far--IR selected sample, on which numerous studies of
galaxy evolution are based. Here we present and... | The Cosmic Microwave Background and $H_0$: The cosmic microwave background (CMB) offers a unique window into the early
universe, providing insights into cosmological parameters like the Hubble
constant. Recent precise measurements of the CMB by experiments like Planck
seem to point to a lower value for the Hubble const... |
Gravitational Fragmentation in Galaxy Mergers: A Stability Criteria: We study the gravitational stability of gaseous streams in the complex
environment of a galaxy merger, because mergers are known to be places of
ongoing massive cluster formation and bursts of star formation. We find an
analytic stability parameter fo... | Constraints on dark matter interactions with standard model particles
from CMB spectral distortions: We propose a new method to constrain elastic scattering between dark matter
(DM) and standard model particles in the early Universe. Direct or indirect
thermal coupling of non-relativistic DM with photons leads to a h... |
Beyond the Ultra-deep Frontier Fields And Legacy Observations (BUFFALO):
a high-resolution strong + weak-lensing view of Abell 370: The HST treasury program BUFFALO provides extended wide-field imaging of the
six Hubble Frontier Fields galaxy clusters. Here we present the combined strong
and weak-lensing analysis of ... | The Correlated Formation Histories of Massive Galaxies and Their Dark
Matter Halos: Using observations in the COSMOS field, we report an intriguing correlation
between the star formation activity of massive (~10^{11.4}\msol) central
galaxies, their stellar masses, and the large-scale (~10 Mpc) environments of
their g... |
Scale-invariant helical magnetic field evolution and the duration of
inflation: We consider a scale-invariant helical magnetic field generated during
inflation. We show that, if the mean magnetic helicity density of such a field
is measured, it can be used to determine a lower bound on the duration of
inflation. Uppe... | Modelling Time-varying Dark Energy with Constraints from Latest
Observations: We introduce a set of two-parameter models for the dark energy equation of
state (EOS) $w(z)$ to investigate time-varying dark energy. The models are
classified into two types according to their boundary behaviors at the redshift
$z=(0,\inf... |
Quantitative Constraints on the Reionization History from the IGM
Damping Wing Signature in Two Quasars at z > 7: During reionization, neutral hydrogen in the intergalactic medium (IGM)
imprints a damping wing absorption feature on the spectrum of high-redshift
quasars. A detection of this signature provides compelli... | The Formation History of the Ultra-Faint Dwarf Galaxies: We present early results from a Hubble Space Telescope survey of the
ultra-faint dwarf galaxies. These Milky Way satellites were discovered in the
Sloan Digital Sky Survey, and appear to be an extension of the classical dwarf
spheroidals to low luminosities, offe... |
Navarro-Frenk-White dark matter profile and the dark halos around disk
systems: The $\Lambda$ cold dark matter ($\Lambda$CDM) scenario well describes the
Universe at large scales, but shows some serious difficulties at small scales:
the inner dark matter (DM) density profiles of spiral galaxies generally appear
to be... | The effect of massive neutrinos on the BAO peak: We study the impact of neutrino masses on the shape and height of the BAO
peak of the matter correlation function, both in real and redshift space. In
order to describe the nonlinear evolution of the BAO peak we run N-body
simulations and compare them with simple analyti... |
ISiTGR: Testing deviations from GR at cosmological scales including
dynamical dark energy, massive neutrinos, functional or binned
parametrizations, and spatial curvature: We introduce a new version of the Integrated Software in Testing General
Relativity (ISiTGR) which is a patch to the software CAMB and CosmoMC. ... | Towards a model-independent reconstruction approach for late-time Hubble
data: Gaussian processes offers a convenient way to perform nonparametric
reconstructions of observational data assuming only a kernel which describes
the covariance between neighbouring points in a data set. We approach the
ambiguity in the cho... |
Galaxy clusters as intrinsic alignment tracers: present and future: Galaxies and clusters embedded in the large-scale structure of the Universe
are observed to align in preferential directions. Galaxy alignment has been
established as a potential probe for cosmological information, but the
application of cluster alignm... | Evidence for a correlation between the sizes of quiescent galaxies and
local environment to z ~ 2: We present evidence for a strong relationship between galaxy size and
environment for the quiescent population in the redshift range 1 < z < 2.
Environments were measured using projected galaxy overdensities on a scale ... |
Cosmological Constraints on Higgs-Dilaton Inflation: We test the viability of the Higgs-dilaton model (HDM) compared to the
evolving dark energy ($w_0 w_a$CDM) model, in which the cosmological constant
model $\Lambda$CDM is also nested, by using the latest cosmological data that
includes the cosmic microwave background... | High Sensitivity Array Observations of the z=1.87 Sub-Millimeter Galaxy
GOODS 850-3: We present sensitive phase-referenced VLBI results on the radio continuum
emission from the z=1.87 luminous submillimeter galaxy (SMG) GOODS 850-3. The
observations were carried out at 1.4 GHz using the High Sensitivity Array
(HSA). ... |
Cosmography and cosmic acceleration: We investigate the prospects for determining the accelerating history of the
Universe from upcoming measurements of the expansion rate $H(z)$. In our
analyses, we use Monte Carlo simulations based on $w$CDM models to generate
samples with different characteristics and calculate the ... | Lensing-induced morphology changes in CMB temperature maps in modified
gravity theories: Lensing of the Cosmic Microwave Background (CMB) changes the morphology of
pattern of temperature fluctuations, so topological descriptors such as
Minkowski Functionals can probe the gravity model responsible for the lensing.
We ... |
Intrinsic galaxy shapes and alignments I: Measuring and modelling COSMOS
intrinsic galaxy ellipticities: The statistical properties of the ellipticities of galaxy images depend on
how galaxies form and evolve, and therefore constrain models of galaxy
morphology, which are key to the removal of the intrinsic alignment... | Void Lensing as a Test of Gravity: We investigate the potential of weak lensing by voids to test for deviations
from General Relativity. We calculate the expected lensing signal of a scalar
field with derivative couplings, finding that it has the potential to boost the
tangential shear both within and outside the void ... |
The Cosmological Effect of CMB/BAO Measurements: In this paper, the CMB/BAO measurements which cover the 13 redshift data in
the regime $0.106 \leq z \leq 2.34$ are given out. The CMB/BAO samples are
based on the BAO distance ratios $r_{s}(z_d)/D_{V}(z)$ and the CMB acoustic
scales $l_{A}$. It could give out the accele... | Small-Scale Challenges to the $Λ$CDM Paradigm: The dark energy plus cold dark matter ($\Lambda$CDM) cosmological model has
been a demonstrably successful framework for predicting and explaining the
large-scale structure of Universe and its evolution with time. Yet on length
scales smaller than $\sim 1$ Mpc and mass sca... |
Improving Statistical Sensitivity of X-ray Searches for Axion-Like
Particles: X-ray observations of bright AGNs in or behind galaxy clusters offer unique
capabilities to constrain axion-like particles (ALPs). Existing analysis
technique rely on measurements of the global goodness-of-fit. We develop a new
analysis met... | Convolution Lagrangian perturbation theory for biased tracers beyond
general relativity: We compare analytic predictions for real and Fourier space two-point
statistics for biased tracers from a variety of Lagrangian Perturbation Theory
approaches against those from state of the art N-body simulations in $f(R)$
Hu-Sa... |
Complex particle acceleration processes in the hotspots of 3C105 and
3C445: We investigate the nature of the broad-band emission associated with the
low-power radio hotspots 3C105 South and 3C445 South. Both hotspot regions are
resolved in multiple radio/optical components. High-sensitivity radio VLA,
NIR/optical VLT... | Density split statistics: joint model of counts and lensing in cells: We present density split statistics, a framework that studies lensing and
counts-in-cells as a function of foreground galaxy density, thereby providing a
large-scale measurement of both 2-point and 3-point statistics. Our method
extends our earlier w... |
The BEHOMO project: $Λ$LTB $N$-body simulations: Our Universe may feature large-scale inhomogeneities and anisotropies which
cannot be explained by the standard model of cosmology, that is, the
homogeneous and isotropic FLRW metric, on which the $\Lambda$CDM model is
built, may not describe accurately observations. Cur... | Status of QUBIC, the Q&U Bolometric Interferometer for Cosmology: The Q&U Bolometric Interferometer for Cosmology (QUBIC) is a novel kind of
polarimeter optimized for the measurement of the $B$-mode polarization of the
Cosmic Microwave Background (CMB), which is one of the major challenges of
observational cosmology. T... |
The strongest bounds on active-sterile neutrino mixing after Planck data: Light sterile neutrinos can be excited by oscillations with active neutrinos
in the early universe. Their properties can be constrained by their
contribution as extra-radiation, parameterized in terms of the effective number
of neutrino species N... | Cosmology with XMM galaxy clusters: the X-CLASS/GROND catalogue and
photometric redshifts: The XMM Cluster Archive Super Survey (X-CLASS) is a serendipitously-detected
X-ray-selected sample of 845 galaxy clusters based on 2774 XMM archival
observations and covering approximately 90 deg$^2$ spread across the
high-Gala... |
Synthetic simulations of the extragalactic sky seen by eROSITA. I.
Pre-launch selection functions from Monte-Carlo simulations: Studies of galaxy clusters provide stringent constraints on models of
structure formation. Provided that selection effects are under control, large
X-ray surveys are well suited to derive co... | Pairwise Transverse Velocity Measurement with the Rees-Sciama Effect: We introduce a new estimator for the mean pairwise velocities of galaxy
clusters, which is based on the measurement of the clusters'
$\textit{transverse}$ velocity components. The Rees-Sciama (RS) effect offers
an opportunity to measure transverse pe... |
Gas Emission Spectrum in the Irr Galaxy IC 10: Spectroscopic long-slit observations of the dwarf Irr galaxy IC 10 were
conducted at the 6-m Special Astrophysical Observatory telescope with the
SCORPIO focal reducer. The ionized-gas emission spectra in the regions of
intense current star formation were obtained for a la... | Growth of curvature perturbations for PBH formation \& detectable GWs in
non-minimal curvaton scenario revisited: We revisit the growth of curvature perturbations in non-minimal curvaton
scenario with a non-trivial field metric $\lambda(\phi)$ where $\phi$ is an
inflaton field, and incorporate the effect from the non... |
Empirically-Driven Multiwavelength K-corrections At Low Redshift: K-corrections, conversions between flux in observed bands to flux in
rest-frame bands, are critical for comparing galaxies at various redshifts.
These corrections often rely on fits to empirical or theoretical spectral
energy distribution (SED) templates... | The Arecibo Legacy Fast ALFA Survey: VIII. HI Source Catalog of the
Anti-Virgo Region at dec = +25 deg: We present a fourth catalog of HI sources from the Arecibo Legacy Fast ALFA
(ALFALFA) Survey. We report 541 detections over 136 deg2, within the region of
the sky having 22h < R.A. < 03h and 24 deg < Dec. < 26 deg ... |
Spatial density fluctuations and selection effects in galaxy redshift
surveys: One of the main problems of observational cosmology is to determine the range
in which a reliable measurement of galaxy correlations is possible. This
corresponds to determine the shape of the correlation function, its possible
evolution w... | Systematics in Metallicity Gradient Measurements I : Angular Resolution,
Signal-to-Noise and Annuli Binning: With the rapid progress in metallicity gradient studies at high-redshift, it
is imperative that we thoroughly understand the systematics in these
measurements. This work investigates how the [NII]/Halpha ratio... |
The elaboration of spiral galaxies: morpho-kinematics analyses of their
progenitors with IMAGES: The IMAGES project aims at measuring the velocity fields of a representative
sample of 100 massive galaxies at z=0.4-0.75, selected in the CDFS, the CFRS
and the HDFS fields. It uses the world-unique mode of multiple inte... | The evolution of AGN across cosmic time: what is downsizing?: We use a coupled model of the formation and evolution of galaxies and black
holes (BH) to study the evolution of active galactic nuclei (AGN) in a cold
dark matter universe. The model predicts the BH mass, spin and mass accretion
history. BH mass grows via a... |
Can galaxy evolution mimic cosmic reionization?: Lyman-$\alpha$ (Ly$\alpha$) emitting galaxies are powerful tools to probe the
late stages of cosmic reionization. The observed sudden drop in Ly$\alpha$
fraction at $z>6$ is often interpreted as a sign of reionization, since the
intergalactic medium (IGM) is more neutral... | Quantifying the behaviour of curvature perturbations during inflation: How much does the curvature perturbation change after it leaves the horizon,
and when should one evaluate the power spectrum? To answer these questions we
study single field inflation models numerically, and compare the evolution of
different curvat... |
Gravitational Radiation from First-Order Phase Transitions: It is believed that first-order phase transitions at or around the GUT scale
will produce high-frequency gravitational radiation. This radiation is a
consequence of the collisions and coalescence of multiple bubbles during the
transition. We employ high-resolu... | CANDELS+3D-HST: compact SFGs at z~2-3, the progenitors of the first
quiescent galaxies: We analyze the star-forming and structural properties of 45 massive
(log(M/Msun)>10) compact star-forming galaxies (SFGs) at 2<z<3 to explore
whether they are progenitors of compact quiescent galaxies at z~2. The
optical/NIR and f... |
Constraining Inflationary Scenarios with Braneworld Models and Second
Order Cosmological Perturbations: Inflationary cosmology is the leading explanation of the very early universe.
Many different models of inflation have been constructed which fit current
observational data. In this work theoretical and numerical me... | Star-Forming Galaxies at z~2 in the Hubble Ultra Deep Field: Using a simple color selection based on B-, z- and K-band photometry, BzK=
(z-K)_AB-(B-z)_AB>-0.2, we picked out 52 star-forming galaxies at 1.4<z<2.5
(sBzKs) from a K-band selected sample (K_Vega<22.0) in an area of ~5.5 arcmin^2
of the Hubble Ultra Deep Fie... |
Strongly Scale-dependent Non-Gaussianity: We discuss models of primordial density perturbations where the
non-Gaussianity is strongly scale-dependent. In particular, the non-Gaussianity
may have a sharp cut-off and be very suppressed on large cosmological scales,
but sizeable on small scales. This may have an impact on... | Alcock-Paczynski effects on wide-angle galaxy statistics: The Alcock-Paczynski (AP) effect is a geometrical distortion in
three-dimensional observed galaxy statistics. In anticipation of precision
cosmology based on ongoing and upcoming all-sky galaxy surveys, we build an
efficient method to compute the AP-distorted co... |
Testing Modified Gravity with Wide Binaries in GAIA DR2: Several recent studies have shown that very wide binary stars can potentially
provide an interesting test for modified-gravity theories which attempt to
emulate dark matter; these systems should be almost Newtonian according to
standard dark-matter theories, whil... | On the simulation of gravitational lensing: Gravitational lensing refers to the deflection of light by the gravity of
celestial bodies, often predominantly composed of dark matter. Seen through a
gravitational lens, the images of distant galaxies appear distorted. In this
paper we discuss simulation of the image distor... |
Bayesian hierarchical modelling of weak lensing - the golden goal: To accomplish correct Bayesian inference from weak lensing shear data
requires a complete statistical description of the data. The natural framework
to do this is a Bayesian Hierarchical Model, which divides the chain of
reasoning into component steps. ... | The surprising accuracy of isothermal Jeans modelling of
self-interacting dark matter density profiles: Recent claims of observational evidence for self-interacting dark matter
(SIDM) have relied on a semi-analytic method for predicting the density
profiles of galaxies and galaxy clusters containing SIDM. We present ... |
Statistical mechanics of collisionless orbits. II. Structure of halos: In this paper, we present the density, \rho, velocity dispersion, \sigma, and
\rho/\sigma^3 profiles of isotropic systems which have the energy distribution,
N(E)\propto[\exp(\phi_0-E)-1], derived in Paper I. This distribution, dubbed
DARKexp, is th... | 13CO 1-0 imaging of the Medusa merger, NGC4194: Studying molecular gas properties in merging galaxies gives important clues
to the onset and evolution of interaction-triggered starbursts. The CO/13CO 1-0
line intensity ratio can be used as a tracer of how dynamics and star formation
processes impact the gas properties.... |
Submillimetre observations of galaxy clusters with BLAST: the
star-formation activity in Abell 3112: We present observations at 250, 350, and 500 um of the nearby galaxy cluster
Abell 3112 (z=0.075) carried out with BLAST, the Balloon-borne Large Aperture
Submillimeter Telescope. Five cluster members are individually... | Constraining dark photons and their connection to 21 cm cosmology with
CMB data: In the inhomogeneous Universe, the cosmological conversion of dark photons
into ordinary photons (and vice versa) may happen at a great number of
resonance redshifts. This alters the CMB observed energy spectrum and degree of
small-scale... |
Fractional Polarisation of Extragalactic Sources in the
500-square-degree SPTpol Survey: We study the polarisation properties of extragalactic sources at 95 and 150
GHz in the SPTpol 500 deg$^2$ survey. We estimate the polarised power by
stacking maps at known source positions, and correct for noise bias by
subtracti... | Under Einstein's Microscope: Measuring Properties of Individual Rotating
Massive Stars From Extragalactic Micro Caustic Crossings: Highly magnified stars residing in caustic crossing lensed galaxies at z ~
0.7-1.5 in galaxy cluster lensing fields inevitably exhibit recurrent
brightening events as they traverse a micr... |
The BINGO Project I: Baryon Acoustic Oscillations from Integrated
Neutral Gas Observations: Observations of the redshifted 21-cm line of neutral hydrogen (HI) are a new
and powerful window of observation that offers us the possibility to map the
spatial distribution of cosmic HI and learn about cosmology. BINGO (Bary... | Towards Accurate Modeling of Line-Intensity Mapping One-Point
Statistics: Including Extended Profiles: Line-intensity mapping (LIM) is quickly attracting attention as an
alternative technique to probe large-scale structure and galaxy formation and
evolution at high redshift. LIM one-point statistics are motivated bec... |
CONCERTO: Extracting the power spectrum of the [C II ] emission line: CONCERTO is the first experiment to perform a [CII] line intensity mapping
survey to target $z>5.2$. Measuring the [CII] power spectrum allows us to study
the role of dusty star-forming galaxies in the star formation history during
the Reionization a... | Effective Cross Section of Fuzzy Dark Matter Halos: We numerically study the movement of two colliding fuzzy dark matter solitons
without explicit self-interaction and find the effective cross section of
dissipative change in velocity. The cross section turns out to be inversely
proportional to the velocity cubed, and ... |
Correlations of Dark Matter, Gas and Stellar Profiles in Dark Matter
Halos: Halos of similar mass and redshift exhibit a large degree of variability in
their differential properties, such as dark matter, hot gas, and stellar mass
density profiles. This variability is an indicator of diversity in the
formation history... | The early early type: discovery of a passive galaxy at z=3: We present the discovery of a massive, quiescent galaxy at z=2.99. We have
obtained a HST/WFC3 spectrum of this object and measured its redshift from the
detection of a deep 4000A break consistent with an old population and a high
metallicity. By stellar popul... |
Constraining f(R) theories with Type Ia Supernovae and Gamma Ray Bursts: Fourth - order gravity theories have received much interest in recent years
thanks to their ability to provide an accelerated cosmic expansion in a matter
only universe. In these theories, the Lagrangian density of the gravitational
field has the ... | The Minimum Testable Abundance of Primordial Black Holes at Future
Gravitational-Wave Detectors: The next generation of gravitational-wave experiments, such as Einstein
Telescope, Cosmic Explorer and LISA, will test the primordial black hole
scenario. We provide a forecast for the minimum testable value of the abunda... |
Quasidecoupled state for dark matter in nonstandard thermal histories: Dark matter drops out of kinetic equilibrium with standard model particles
when the momentum-transfer rate equals the expansion rate. In a
radiation-dominated universe, this occurs at essentially the same time as dark
matter kinetically decouples fr... | Numerical modelling of the lobes of radio galaxies in cluster
environments: We have carried out two-dimensional, axisymmetric, hydrodynamic numerical
modelling of the evolution of radio galaxy lobes. The emphasis of our work is
on including realistic hot-gas environments in the simulations and on
establishing what pr... |
Gamma Ray Bursts as Probes of the Distant Universe: We review recent results on the high-redshift universe and the cosmic
evolution obtained using Gamma Ray Bursts (GRBs) as tracers of high-redshift
galaxies. Most of the results come from photometric and spectroscopic
observations of GRB host galaxies once the afterglo... | Lensing covariance on cut sky and SPT-Planck lensing tensions: We investigate correlations induced by gravitational lensing on simulated
cosmic microwave background data of experiments with an incomplete sky coverage
and their effect on inferences from the South Pole Telescope data. These
correlations agree well with t... |
Structure and Substructure of Galactic Spheroids: The full spatio-chemo-dynamical structure of galaxies of all types and
environments at low redshift provides a critical accompaniment to observations
of galaxy formation at high redshift. The next decade brings the observational
opportunity to strongly constrain nearby ... | Self-annihilating dark matter and the CMB: reionizing the Universe and
constraining cross sections: I summarize the recent advances in determining the effects of
self-annihilating WIMP dark matter on the modification of the recombination
history, at times earlier than the formation of astrophysical objects.
Depending... |
Agora: Multi-Component Simulation for Cross-Survey Science: The tightest cosmological constraints currently available are obtained by
combining complementary data sets. When combining correlated data sets, various
astrophysical biases that affect the measurements must be identified and
treated. There are numerous such ... | Constraints on primordial black holes in the mixed dark matter scenarios
using the ratio $\rm (^3{He}+D)/H$: We derive the upper limit on the dark matter (DM) fraction in primordial
black holes (PBHs) in the mixed DM scenarios. In this scenarios, a PBH can
accrete weakly interacting massive particles (WIMPs) to form ... |
The Radio Signatures of the First Supernovae: Primordial stars are key to primeval structure formation as the first stellar
components of primeval galaxies, the sources of cosmic chemical enrichment and
likely cosmic reionization, and they possibly gave rise to the supermassive
black holes residing at the centres of ga... | CMB Bispectrum from Primordial Scalar, Vector and Tensor
non-Gaussianities: We present an all-sky formalism for the Cosmic Microwave Background (CMB)
bispectrum induced by the primordial non-Gaussianities not only in scalar but
also in vector and tensor fluctuations. We find that the bispectrum can be
formed in an ex... |
A Counterpart to the Radial Orbit Instability in Triaxial Stellar
Systems: Self-consistent solutions for triaxial mass models are highly non-unique. In
general, some of these solutions might be dynamically unstable, making them
inappropriate as descriptions of steady-state galaxies. Here we demonstrate for
the first ... | Clustering of Low-Redshift (z <= 2.2) Quasars from the Sloan Digital Sky
Survey: We present measurements of the quasar two-point correlation function,
\xi_{Q}, over the redshift range z=0.3-2.2 based upon data from the SDSS. Using
a homogeneous sample of 30,239 quasars with spectroscopic redshifts from the
DR5 Quasar... |
Discovery of the X-ray selected galaxy cluster XMMU J0338.8+0021 at z =
1.49 - Indications for a young system with a forming brightest galaxy: We report on the discovery of a galaxy cluster at z = 1.490 originally
selected as an extended X-ray source in the XMM-Newton Distant Cluster Project.
Further observations car... | Impact of Anisotropic Birefringence on Measuring Cosmic Microwave
Background Lensing: The power spectrum of cosmic microwave background lensing is a powerful tool
for constraining fundamental physics such as the sum of neutrino masses and the
dark energy equation of state. Current lensing measurements primarily come ... |
Cross-correlation of DES Y3 lensing and ACT/${\it Planck}$ thermal
Sunyaev Zel'dovich Effect II: Modeling and constraints on halo pressure
profiles: Hot, ionized gas leaves an imprint on the cosmic microwave background via the
thermal Sunyaev Zel'dovich (tSZ) effect. The cross-correlation of gravitational
lensing (... | Exploring Interacting Dark Energy with Chaos Quantum-Behaved Particle
Swarm Optimization: Models with an interaction between dark energy and dark matter have already
been studied for about twenty years. However, in this paper, we provide for the
first time a general analytical solution for models with an energy trans... |
Binary Black Holes, Gas Sloshing, and Cold Fronts in the X-ray Halo
Hosting 4C+37.11: We analyzed deep $Chandra$ ACIS-I exposures of the cluster-scale X-ray halo
surrounding the radio source 4C+37.11. This remarkable system hosts the closest
resolved pair of super-massive black hole and an exceptionally luminous
elli... | First stars in Damped Lyman Alpha systems: In order to characterize Damped Lyman Alpha systems (DLAs) potentially
hosting first stars, we present a novel approach to investigate DLAs in the
context of Milky Way (MW) formation, along with their connection with the most
metal-poor stars and local dwarf spheroidal (dSph) ... |
Accessing the Acceleration of the Universe with Sunyaev-Zel'dovich and
X-ray Data from Galaxy Clusters: By using exclusively the Sunyaev-Zel'dovich effect and X-ray surface
brightness data from 25 galaxy clusters in the redshift range 0.023< z < 0.784
we access cosmic acceleration employing a kinematic description. S... | Constraining the Expansion History and Early Dark Energy with Line
Intensity Mapping: We consider the potential for line intensity mapping (IM) experiments to
measure the baryon acoustic oscillations (BAO) from 3 < z < 6. This would
constrain the expansion history in a redshift range that is currently
unexplored. We ... |
Modelling the relative velocities of isolated pairs of galaxies: We study the comoving relative velocities, v12, of model isolated galaxy
pairs at z=0.5. For this purpose, we use the predictions from the GALFORM
semi-analytical model of galaxy formation and evolution based on a Lambda cold
dark matter cosmology consist... | Observational Scan Induced Artificial CMB Anisotropy: To reliably detect the cosmic microwave background (CMB) anisotropy is of
great importance in understanding the birth and evolution of the Universe. One
of the difficulties in CMB experiments is the domination of measured CMB
anisotropy maps by the Doppler dipole mo... |
Dipole Distortions in the Intergalactic Medium: Baryonic feedback can significantly modify the spatial distribution of matter
on small scales and create a bulk relative velocity between the dominant cold
dark matter and the hot gas. We study the consequences of such bulk motions
using two high resolution hydrodynamic s... | Polycyclic Aromatic Hydrocarbons in Galaxies at z~0.1: the Effect of
Star Formation and AGN: We present the analysis of the Polycyclic Aromatic Hydrocarbon (PAH) spectra
of a sample of 92 typical star forming galaxies at 0.03 < z < 0.2 observed with
the Spitzer IRS. We compare the relative strengths of PAH emission f... |
Mock data sets for the Eboss and DESI Lyman-$α$ forest surveys: {We present a publicly-available code to generate mock Lyman-$\alpha$ (\lya)
forest data sets. The code is based on the Fluctuating Gunn-Peterson
Approximation (FGPA) applied to Gaussian random fields and on the use of fast
Fourier transforms (FFT). The ou... | Joint Measurement of Lensing-Galaxy Correlations Using SPT and DES SV
Data: We measure the correlation of galaxy lensing and cosmic microwave background
lensing with a set of galaxies expected to trace the matter density field. The
measurements are performed using pre-survey Dark Energy Survey (DES) Science
Verificat... |
The specific frequencies of ultra-compact dwarf galaxies: We aim at quantifying the specific frequency of UCDs in a range of
environments and at relating this to the frequency of globular clusters (GCs)
and potential progenitor dwarf galaxies. Are the frequencies of UCDs consistent
with being the bright tail of the GC ... | Observations of environmental quenching in groups in the 11 Gyr since
z=2.5: different quenching for central and satellite galaxies: We present direct observational evidence for star formation quenching in
galaxy groups in the redshift range 0<z<2.5. We utilize a large sample of
nearly 6000 groups, selected by fixed ... |
An independent search for annual modulation and its significance in
ANAIS-112 data: We perform an independent search for sinusoidal-based modulation in the
recently released ANAIS-112 data, which could be induced by dark matter
scatterings. We then evaluate this hypothesis against the null hypothesis that
the data co... | On the exclusion of intra-cluster plasma from AGN-blown bubbles: Simple arguments suggest that magnetic fields should be aligned tangentially
to the surface of an AGN-blown bubble. If this is the case, charged particles
from the fully ionised intra-cluster medium (ICM) will be prevented,
ordinarily, from crossing the b... |
Detectability of Cosmic Dark Flow in the Type Ia Supernova
Redshift-Distance Relation: We re-analyze the detectability of large scale dark flow (or local bulk flow)
with respect to the CMB background based upon the redshift-distance relation
for Type Ia supernovae (SN Ia). We made two independent analyses: one based
... | Carnegie Supernova Project: Observations of Type IIn supernovae: The observational diversity displayed by various Type IIn supernovae (SNe
IIn) is explored and quantified. In doing so, a more coherent picture ascribing
the variety of observed SNe IIn types to particular progenitor scenarios is
sought. Carnegie Supernov... |
Gravitational Waves from Binary Mergers of Sub-solar Mass Dark Black
Holes: We explore the possible spectrum of binary mergers of sub-solar mass black
holes formed out of dark matter particles interacting via a dark
electromagnetism. We estimate the properties of these dark black holes by
assuming that their formatio... | A short mean free path at $z=6$ favors late and rapid reionization by
faint galaxies: Recent measurements of the ionizing photon mean free path
($\lambda_{912}^{\rm mfp}$) at $5 < z < 6$ suggest that the IGM was rapidly
evolving at those times. We use radiative transfer simulations to explore the
implications for rei... |
Simulations of MHD Instabilities in Intracluster Medium Including
Anisotropic Thermal Conduction: We perform a suite of simulations of cooling cores in clusters of galaxies in
order to investigate the effect of the recently discovered heat flux buoyancy
instability (HBI) on the evolution of cores. Our models follow t... | Revisiting Cardassian Model and Cosmic Constraint: In this paper, we revisit the Cardassian model in which the radiation energy
component is included. It is important for early epoch when the radiation
cannot be neglected because the equation of state (EoS) of the effective dark
energy becomes time variable. Therefore,... |
Transient dark energy, cosmological constant boundary crossing and dark
energy $w(z)$ data fits: The formalism of dark energy based on modeling speed of sound as a function
of equation of state parameter is elaborated. A specific model which allows
detailed study of cosmological constant boundary crossing is introduc... | Phase Transition Generated Cosmological Magnetic Field at Large Scales: We constrain a primordial magnetic field (PMF) generated during a phase
transition (PT) using the big bang nucleosynthesis bound on the relativistic
energy density. The amplitude of the PMF at large scales is determined by the
shape of the PMF spec... |
The Effects of an AGN on Host Galaxy Colour and Morphology Measurements: We assess the effects of simulated active galactic nuclei (AGNs) on the
colour and morphology measurements of their host galaxies. To test the
morphology measurements, we select a sample of galaxies not known to host AGNs
and add a series of point... | Non-linear Fields in Generalized Cosmologies: The perturbative approach to structure formation has recently received a lot
of attention in the literature. In such setups the final predictions for
observables like the power spectrum is often derived under additional
approximations such as a simplified time dependence. H... |
Cosmic opacity: cosmological-model-independent tests from gravitational
waves and Type Ia Supernova: In this paper, we present a scheme to investigate the opacity of the Universe
in a cosmological-model-independent way, with the combination of current and
future available data in gravitational wave (GW) and electroma... | The Role of Groups in Galaxy Evolution: compelling evidence of
pre-processing out to the turnaround radius of clusters: We present clear and direct evidence of the pre-processing effect of group
galaxies falling into clusters in the local Universe ($z \lesssim 0.1$). We
start with a sample of 238 clusters, from which... |
NGC 6340: an old S0 galaxy with a young polar disc. Clues from
morphology, internal kinematics and stellar populations: Lenticular galaxies are believed to form by a combination of environmental
effects and secular evolution. We study the nearby disc-dominated S0 galaxy NGC
6340 photometrically and spectroscopically ... | Deep 1.1 mm-wavelength imaging of the GOODS-South field by AzTEC/ASTE --
II. Redshift distribution and nature of the submillimetre galaxy population: We report the results of the counterpart identification and a detailed
analysis of the physical properties of the 48 sources discovered in our deep
1.1mm wavelength ima... |
Lyth bound revisited: Imposing that the excursion distance of inflaton in field space during
inflation be less than the Planck scale, we derive an upper bound on the
tensor-to-scalar ratio at the CMB scales, i.e. $r_{*,max}$, in the general
canonical single-field slow-roll inflation model, in particular the model with
... | The Galaxy Cluster Concentration-Mass Scaling Relation: Scaling relations of clusters have made them particularly important
cosmological probes of structure formation. In this work, we present a
comprehensive study of the relation between two profile observables,
concentration ($\mathrm{c_{vir}}$) and mass ($\mathrm{M_... |
Tachyon stars: We consider a self-gravitating body composed of ideal Fermi gas of tachyons
at zero temperature. The Oppenheimer-Volkoff equation is solved for various
central densities and various tachyon mass parameter $m$. Although a pure
tachyon star has finite mass, it cannot occur in nature because the equilibrium... | Probing reionization using quasar near-zones at redshift z ~ 6: Using hydrodynamical simulations coupled to a radiative transfer code, we
study the additional heating effects in the intergalactic medium (IGM) produced
by $z\sim 6$ quasars in their near-zones. If helium is predominantly in HeII to
begin with, both norma... |
Inflation models in the light of self-interacting sterile neutrinos: Short baseline neutrino experiments, like LSND and MiniBooNE experiments,
pointed towards the existence of eV mass scale sterile neutrinos. To reconcile
sterile neutrinos with cosmology self interaction between sterile neutrinos has
been studied. We a... | Large-Scale Structure in Brane-Induced Gravity I. Perturbation Theory: We study the growth of subhorizon perturbations in brane-induced gravity
using perturbation theory. We solve for the linear evolution of perturbations
taking advantage of the symmetry under gauge transformations along the
extra-dimension to decouple... |
KiDS-1000 Cosmology: constraints beyond flat $Λ$CDM: We present constraints on extensions to the flat $\Lambda$CDM cosmological
model by varying the spatial curvature $\Omega_K$, the sum of the neutrino
masses $\sum m_\nu$, the dark energy equation of state parameter $w$, and the
Hu-Sawicki $f(R)$ gravity $f_{R0}$ para... | TDCOSMO X. Automated Modeling of 9 Strongly Lensed Quasars and
Comparison Between Lens Modeling Software: To use strong gravitational lenses as an astrophysical or cosmological probe,
models of their mass distributions are often needed. We present a new,
time-efficient automation code for uniform modeling of strongly... |
Emission line - radio correlation for Low Luminosity Compact sources.
Evolution schemes: We present radio and optical analysis of a sample of Low Luminosity Compact
(LLC) objects, selected from FIRST survey and observed with MERLIN at L-band
and C-band. The main criterion used for selection was luminosity of the obje... | Early structure formation from cosmic string loops: We examine the effects of cosmic strings on structure formation and on the
ionization history of the universe. While Gaussian perturbations from inflation
are known to provide the dominant contribution to the large scale structure of
the universe, density perturbation... |
Finding Rare AGN: XMM-Newton and Chandra Observations of SDSS Stripe 82: We have analyzed the {\it XMM-Newton} and {\it Chandra} data overlapping
$\sim$16.5 deg$^2$ of Sloan Digital Sky Survey Stripe 82, including $\sim$4.6
deg$^2$ of proprietary {\it XMM-Newton} data that we present here. In total,
3362 unique X-ray s... | Toward the low-scatter selection of X-ray clusters: Galaxy cluster
detection with eROSITA through cluster outskirts: One key ingredient in using galaxy clusters (GCs) as a precision cosmological
probe in large X-ray surveys is to understand selection effects. The dependence
of the X-ray emission on the square of the ... |
High resolution spectroscopy of the three dimensional cosmic web with
close QSO groups: We study the three-dimensional distribution of matter at z~2 using high
resolution spectra of QSO pairs and simulated spectra drawn from cosmological
hydro-dynamical simulations. We present a sample of 15 QSOs, corresponding to
21... | A SAURON study of dwarf elliptical galaxies in the Virgo Cluster: Dwarf elliptical galaxies are the most common galaxy type in nearby galaxy
clusters, yet they remain relatively poorly studied objects and many of their
basic properties have yet to be quantified. In this contribution we present the
preliminary results o... |
Sunyaev-Zel'dovich contribution in CMB analysis: The Sunyaev-Zel'dovich (SZ) effect has long been identified as one of the
most important secondary effects of the Cosmic Microwave Background (CMB). On
the one hand, it is a potentially very powerful cosmological probe providing us
with additional constraints and on the ... | Enhanced accretion rates of stars on Super-massive Black Holes by
star-disk interactions in galactic nuclei: We investigate the dynamical interaction of a central star cluster
surrounding a super-massive black hole and a central accretion disk. The
dissipative force acting on stars in the disk leads to an enhanced ma... |
The MillenniumTNG Project: The large-scale clustering of galaxies: Modern redshift surveys are tasked with mapping out the galaxy distribution
over enormous distance scales. Existing hydrodynamical simulations, however, do
not reach the volumes needed to match upcoming surveys. We present results for
the clustering of ... | Velocities hasten to tell us about the Universe: The peculiar velocities of galaxies are driven by gravity, and hence hold the
promise of probing details of how gravity forms structures. In particular it is
possible to constrain cosmological parameters and to test extensions to the
standard model, such as modifications... |
The Effects of Lyman-Limit Systems on the Evolution and Observability of
the Epoch of Reionization: We present the first large-scale, full radiative transfer simulations of the
reionization of the intergalactic medium in the presence of Lyman-limit systems
(LLSs). To illustrate the impact of LLS opacity, possibly mis... | Host galaxy morphologies of X-ray selected AGN: assessing the
significance of different black hole fueling mechanisms to the accretion
density of the Universe at z~1: We use morphological information of X-ray selected AGN hosts to set limits on
the fraction of the accretion density of the Universe at z~1 that is no... |
Probing early structure and model-independent neutrino mass with
high-redshift CMB lensing mass maps: CMB lensing maps probe the mass distribution in projection out to high
redshifts, but significant sensitivity to low-redshift structure remains. In
this paper we discuss a method to remove the low-redshift contributi... | Bayesian model comparison in cosmology with Population Monte Carlo: We use Bayesian model selection techniques to test extensions of the standard
flat LambdaCDM paradigm. Dark-energy and curvature scenarios, and primordial
perturbation models are considered. To that end, we calculate the Bayesian
evidence in favour of ... |
Impact of a Rapid Diluted Energy Density on the halo mass function: We study dark energy cosmological models, extensions of the standard model of
particles, characterized by having an extra relativistic energy density at very
early times, and that rapidly dilute after a phase transition occurs. These
models generate we... | Mock galaxy shape catalogs in the Subaru Hyper Suprime-Cam Survey: We use the full-sky ray-tracing weak lensing simulations to generate 2268
mock catalogues for the Subaru Hyper Suprime-Cam (HSC) survey first-year shear
catalogue. Our mock catalogues take into account various effects as in the real
data: the survey foo... |
Cosmology on all scales: a two-parameter perturbation expansion: We propose and construct a two-parameter perturbative expansion around a
Friedmann-Lema\^{i}tre-Robertson-Walker geometry that can be used to model
high-order gravitational effects in the presence of non-linear structure. This
framework reduces to the wea... | Primordial Black Holes as Dark Matter: Almost All or Almost Nothing: Primordial black holes (PBHs) are expected to accrete particle dark matter
around them to form ultracompact minihalos (UCMHs), if the PBHs themselves are
not most of the dark matter. We show that if most dark matter is a thermal
relic, then the inner ... |
Evidence for a receding dust sublimation region around a supermassive
black hole: The near-IR emission in Type 1 AGNs is thought to be dominated by the thermal
radiation from dust grains that are heated by the central engine in the
UV/optical and are almost at the sublimation temperature. A brightening of the
central... | A model independent null test on the cosmological constant: We use the Om statistic and the Genetic Algorithms (GA) in order to derive a
null test on the spatially flat cosmological constant model $\Lambda$CDM. This
is done in two steps: first, we apply the GA to the Constitution SNIa data in
order to acquire a model i... |
On the Time Variation of Dust Extinction and Gas Absorption for Type~Ia
Supernovae Observed Through Non-uniform Interstellar Medium: For Type Ia supernovae (SNe Ia) observed through a non-uniform interstellar
medium (ISM) in its host galaxy, we investigate whether the non-uniformity can
cause observable time variatio... | Cosmological Constraints from the Anisotropic Clustering Analysis using
BOSS DR9: Our observations of the Universe are fundamentally anisotropic, with data
from galaxies separated transverse to the line of sight coming from the same
epoch while that from galaxies separated parallel to the line of sight coming
from di... |
Constraining Cosmological Parameters using the Cluster Mass-Richness
Relation: The cluster mass-richness relation (MRR) is an observationally efficient and
potentially powerful cosmological tool for constraining the mean matter density
of the universe and the amplitude of fluctuations using the cluster abundance
tech... | New highly precise weak gravitational lensing flexions measurement
method based on ERA method: Weak gravitational lensing flexions are a kind of weak lensing distortion
which are defined as the spin 1 and spin 3 combinations of the third order
derivatives of gravitational lensing potential. Since the shear has spin 2... |
Measurement and Calibration of Noise Bias in Weak Lensing Galaxy Shape
Estimation: Weak gravitational lensing has the potential to constrain cosmological
parameters to high precision. However, as shown by the Shear TEsting Programmes
(STEP) and GRavitational lEnsing Accuracy Testing (GREAT) Challenges, measuring
gala... | Residual Hubble-bubble effects on supernova cosmology: Even in a universe that is homogeneous on large scales, local density
fluctuations can imprint a systematic signature on the cosmological inferences
we make from distant sources. One example is the effect of a local
under-density on supernova cosmology. Also known ... |
The ALHAMBRA survey: an empirical estimation of the cosmic variance for
merger fraction studies based on close pairs: Our goal is to estimate empirically, for the first time, the cosmic variance
that affects merger fraction studies based on close pairs. We compute the
merger fraction from photometric redshift close p... | WMAP Constraints On K-Inflation: We study the K-Inflation models where the inflaton field has non-canonical
kinetic term. In particular, we consider the Dirac-Born-Infeld (DBI) form for
the kinetic energy of the inflaton field. We consider quadratic and quartic
potentials as well as the potential for the natural inflat... |
Constraining the growth rate on linear scales by combining SKAO and DESI
surveys: In the pursuit of understanding the large-scale structure of the Universe,
the synergy between complementary cosmological surveys has proven to be a
powerful tool. Using multiple tracers of the large-scale structure can
significantly im... | A foreground-marginalized 'BK-lite' likelihood for the tensor-to-scalar
ratio: The current limit on the tensor-to-scalar ratio from the BICEP/Keck
Collaboration (with r<0.036 at 95% confidence) puts pressure on early universe
models, with less than 10% of the error on r attributed to uncertainty in
Galactic foregroun... |
Cosmic voids uncovered -- first-order statistics of depressions in the
biased density field: Cosmic voids are the major volume component in the matter distribution of the
Universe. They posses great potential for constraining dark energy as well as
for testing theories of gravity. Nevertheless, in spite of their grow... | Can we distinguish the adiabatic fluctuations and isocurvature
fluctuations with pulsar timing arrays?: Understanding the nature of primordial fluctuations is critical to our
comprehension of the Universe's early stages. While these fluctuations are
known to be nearly scale-invariant, quasi-adiabatic, and nearly Gaus... |
Observatons of NGC 3077 Galaxy in Narrow Band [SII] and H_alpha Filters: We present observations of the HI tidal arm near dwarf galaxy NGC 3077
(member of the M81 galaxy group) in narrow band [SII] and H_alpha filters.
Observations were carried out in March 2011 with the 2m RCC telescope at NAO
Rozhen, Bulgaria. Our se... | Local observer effect on the cosmological soft theorem: Non-Gaussianities of primordial perturbations in the soft limit provide the
important information about the light degrees of freedom during inflation. The
soft modes of the curvature perturbations, unobservable for a local observer,
act as rescaling the spatial co... |
Radially extended kinematics and stellar populations of the massive
ellipticals NGC1600, NGC4125 and NGC7619. Constraints on the outer dark halo
density profile: We present high quality long slit spectra along the major and minor axes out
to 1.5-2 Re (14-22 kpc) of three bright elliptical galaxies (NGC1600, NGC4125... | Cosmology With Low-Redshift Observations: No Signal For New Physics: We analyse various low-redshift cosmological data from Type-Ia Supernova,
Baryon Acoustic Oscillations, Time-Delay measurements using Strong-Lensing,
$H(z)$ measurements using Cosmic Chronometers and growth measurements from
large scale structure obse... |
Sensitivity of gamma-ray telescopes for detection of magnetic fields in
intergalactic medium: We explore potential of current and next-generation gamma-ray telescopes for
the detection of weak magnetic fields in the intergalactic medium. We
demonstrate that using two complementary techniques, observation of extended
... | On the validity of the Born approximation for weak cosmic flexions: Weak lensing calculations are often made under the assumption of the Born
approximation, where the ray path is approximated as a straight radial line. In
addition, lens-lens couplings where there are several deflections along the
light ray are often ne... |
BeyondPlanck III. Commander3: We describe the computational infrastructure for end-to-end Bayesian CMB
analysis implemented by the BeyondPlanck collaboration. This code is called
commander3, and provides a statistically consistent framework for global
analysis of CMB and microwave observations, and may be useful for a ... | Early dark energy resolution to the Hubble tension in light of weak
lensing surveys and lensing anomalies: Early Dark Energy (EDE) contributing a fraction $f_{\rm EDE}(z_c)\sim 10 \%$
of the energy density of the universe around $z_c\simeq 3500$ and diluting as
or faster than radiation afterwards, can provide a resol... |
A coordinate-independent technique for detecting globally inhomogeneous
flat topologies: A flat Universe model supported by recent observations has 18 possible
choices for its overall topology. To detect or exclude these possibilities is
one of the most important tasks in modern cosmology, but it has been very
diffic... | Assembly Bias of Dwarf-sized Dark Matter Haloes: Previous studies indicate that assembly bias effects are stronger for lower
mass dark matter haloes. Here we make use of high resolution re-simulations of
rich clusters and their surroundings from the Phoenix Project and a large
volume cosmological simulation, the Millen... |
Accurately simulating anisotropic thermal conduction on a moving mesh: We present a novel implementation of an extremum preserving anisotropic
diffusion solver for thermal conduction on the unstructured moving Voronoi mesh
of the AREPO code. The method relies on splitting the one-sided facet fluxes
into normal and obli... | CARMA observations of massive Planck-discovered cluster candidates at
z>0.5 associated with WISE overdensities: Breaking the size-flux degeneracy: We use a Bayesian software package to analyze CARMA-8 data towards 19
unconfirmed Planck SZ-cluster candidates from Rodriguez-Gonzalvez et al.
(2015), that are associated ... |
Star Clusters in M31: Old Clusters with Bar Kinematics: We analyze our accurate kinematical data for the old clusters in the inner
regions of M31. These velocities are based on high S/N Hectospec data (Caldwell
et al 2010). The data are well suited for analysis of M31's inner regions
because we took particular care to ... | 3D simulations with boosted primordial power spectra and ultracompact
minihalos: We perform three-dimensional simulations of structure formation in the early
Universe, when boosting the primordial power spectrum on approximately kpc
scales. We demonstrate that our simulations are capable of producing power-law
profil... |
SDSS J0025-10 at z=0.30: a (U)LIRG to optical QSO transition candidate: We have characterized the amount, spatial distribution and kinematics of the
molecular gas in the merging, double nucleus type 2 quasar SDSS J0025-10 at
z=0.30 using the CO(1-0) transition, based on data obtained with ATCA. This is
one of the scarc... | Reconstructing the shape of the correlation function: We develop an estimator for the correlation function which, in the ensemble
average, returns the shape of the correlation function, even for signals that
have significant correlations on the scale of the survey region. Our estimator
is general and works in any numbe... |
A closer look at the cosmological implications of the $Λ$HDE model: In a previous paper, we proposed a heterotic dark energy model, called
$\Lambda$HDE, in which dark energy is composed of two components: cosmological
constant (CC) and holographic dark energy (HDE). The aim of this work is to
give a more comprehensive ... | Multiple Lensing of the Cosmic Microwave Background anisotropies: We study the gravitational lensing effect on the Cosmic Microwave Background
(CMB) anisotropies performing a ray-tracing of the primordial CMB photons
through intervening large-scale structures (LSS) distribution predicted by
N-Body numerical simulations... |
An Inpainting Approach to Tackle the Kinematic and Thermal SZ Induced
Biases in CMB-Cluster Lensing Estimators: A galaxy cluster's own Sunyaev-Zel{'}dovich (SZ) signal is known to be a
major contaminant when reconstructing the cluster's underlying lensing
potential using cosmic microwave background (CMB) temperature ... | Precise Measurement of the Reionization Optical Depth from The Global
21-cm Signal Accounting for Cosmic Heating: As a result of our limited data on reionization, the total optical depth for
electron scattering, $\tau$, limits precision measurements of cosmological
parameters from the Cosmic Microwave Background (CMB... |
Neutrino properties from cosmology: The interplay between cosmology and earth based experiments is crucial in
order to pin down neutrino physics. Indeed cosmology can provide very tight,
yet model dependent, constraints on some neutrino properties. Here we focus on
the neutrino mass sum, reviewing the up to date curren... | Investigating the Core Morphology-Seyfert Class relationship with Hubble
Space Telescope Archival Images of local Seyfert galaxies: The Unified Model of Active Galactic Nuclei (AGN) has provided a successful
explanation for the observed diversity of AGN in the local Universe. However,
recent analysis of multi-wavelen... |
Search for Low-Mass Dark Matter with CsI(Tl) Crystal Detectors: We present a search for low-mass ($\leq 20 GeV/c^{2}$) weakly interacting
massive particles(WIMPs), strong candidates of dark matter particles,using the
low-background CsI(Tl) detector array of the Korea Invisible Mass Search (KIMS)
experiment. With a tota... | Comment on "Constraining the smoothness parameter and dark energy using
observational H(z) data": In this Comment we discuss a recent analysis by Yu et al. [RAA 11, 125
(2011)] about constraints on the smoothness $\alpha$ parameter and dark energy
models using observational $H(z)$ data. It is argued here that their p... |
Constraining spatial curvature with large-scale structure: We analyse the clustering of matter on large scales in an extension of the
concordance model that allows for spatial curvature. We develop a consistent
approach to curvature and wide-angle effects on the galaxy 2-point correlation
function in redshift space. In... | Anisotropy in the matter distribution beyond the baryonic acoustic
oscillation scale: Tracing the cosmic evolution of the Baryonic Acoustic Oscillation (BAO) scale
with galaxy two point correlation functions is currently the most promising
approach to detect dark energy at early times. A number of ongoing and future
... |
A closer look at interacting dark energy with statefinder hierarchy and
growth rate of structure: We investigate the interacting dark energy models by using the diagnostics of
statefinder hierarchy and growth rate of structure. We wish to explore the
deviations from $\Lambda$CDM and to differentiate possible degenera... | Estimating weak lensing convergence correlation of Type-Ia supernovae
from 5-year SNLS data by internal error estimate technique: We report non-zero weak lensing convergence correlation signal of Type-Ia
supernovae from 5-year Supernovae Legacy Survey data. For our analysis we
utilize 296 supernovae magnification dat... |
The Highest Resolution Mass Map of Galaxy Cluster Substructure To Date
Without Assuming Light Traces Mass: LensPerfect Analysis of Abell 1689: We present a strong lensing mass model of Abell 1689 which resolves
substructures ~25 kpc across (including about ten individual galaxy subhalos)
within the central ~400 kpc d... | Groups of dwarf galaxies in the Local supercluster: We present a project on study of groups composed of dwarf galaxies only. We
selected such structures using HyperLEDA and NED databases with visual
inspection on SDSS images and on digital copy of POSS. The groups are
characterized by size of few tens of kpc and line-o... |
Nonlinear effects of dark energy clustering beyond the acoustic scales: We extend the resummation method of Anselmi & Pietroni (2012) to compute the
total density power spectrum in models of quintessence characterized by a
vanishing speed of sound. For standard $\Lambda$CDM cosmologies, this
resummation scheme allows p... | A Measurement of the Galaxy Group-Thermal Sunyaev-Zel'dovich Effect
Cross-Correlation Function: Stacking cosmic microwave background (CMB) maps around known galaxy clusters
and groups provides a powerful probe of the distribution of hot gas in these
systems via the Sunyaev-Zel'dovich (SZ) effect. A stacking analysis ... |
Mirror dark matter explanation of the DAMA, CoGeNT and CRESST-II data: Dark matter might reside in a hidden sector which contains an unbroken
$U(1)'$ gauge interaction kinetically mixed with standard $U(1)_Y$. Mirror dark
matter provides a well motivated example of such a theory. We show that the
DAMA, CoGeNT and CRESS... | HI intensity mapping with MeerKAT: Calibration pipeline for multi-dish
autocorrelation observations: While most purpose-built 21cm intensity mapping experiments are close-packed
interferometer arrays, general-purpose dish arrays should also be capable of
measuring the cosmological 21cm signal. This can be achieved mo... |
Optical multiband surface photometry of a sample of Seyfert galaxies. I.
Large-scale morphology and local environment analysis of matched Seyfert and
inactive galaxy samples: Parallel analysis of the large-scale morphology and local environment of
matched active and control galaxy samples plays an important role in... | On the Analysis of DLA Kinematics: We discuss two mistreatments of damped Lya (DLA) kinematic analysis that were
first performed by Haehnelt, Steinmetz, & Rauch (1998; hereafter HSR98) and
have recently been repeated by Hong et al. (2010; arXiv:1008.4242v1,
arXiv:1008.4242v2; hereafter H10). Each mistreatment led to th... |
Non-Gaussianity from extragalactic point-sources: The population of compact extragalactic sources contribute to the
non-Gaussianity at Cosmic Microwave Background frequencies. We study their
non-Gaussianity using publicly available full-sky simulations. We introduce a
parametrisation to visualise efficiently the bispec... | The Equation of State of Tracker Fields: We derive the equation of state of tracker fields, which are typical examples
of freezing quintessence (quintessence with the equation of state approaching
toward -1), taking into account of the late-time departure from the tracker
solution due to the nonzero density parameter o... |
Photometric classification and redshift estimation of LSST Supernovae: Supernova (SN) classification and redshift estimation using photometric data
only have become very important for the Large Synoptic Survey Telescope (LSST),
given the large number of SNe that LSST will observe and the impossibility of
spectroscopica... | Galaxy formation on the largest scales: The impact of astrophysics on
the BAO peak: We investigate the effects of galaxy formation on the baryonic acoustic
oscillations (BAO) peak by applying semi-analytic modelling techniques to the
Millennium-XXL, a $3 \times 10^{11}$ particle N-body simulation of similar
volume to... |
Cumulative effects in inflation with ultra-light entropy modes: In multi-field inflation one or more non-adiabatic modes may become light,
potentially inducing large levels of isocurvature perturbations in the cosmic
microwave background. If in addition these light modes are coupled to the
adiabatic mode, they influenc... | How rare is the Bullet Cluster (in a $Λ$CDM universe)?: The Bullet Cluster (1E0657-56) is well-known as providing visual evidence of
dark matter but it is potentially incompatible with the standard $\Lambda$CDM
cosmology due to the high relative velocity of the two colliding clusters.
Previous studies have focussed on ... |
The large-separation expansion of peak clustering in Gaussian random
fields: In the peaks approach, the formation sites of observable structures in the
Universe are identified as peaks in the matter density field. The statistical
properties of the clustering of peaks are particularly important in this
respect. In thi... | Higgs Inflation, Quantum Smearing and the Tensor to Scalar Ratio: In cosmic inflation driven by a scalar gauge singlet field with a tree level
Higgs potential, the scalar to tensor ratio r is estimated to be larger than
0.036, provided the scalar spectral index n_s >= 0.96. We discuss quantum
smearing of these predicti... |
A study of cool core resiliency and entropy mixing in simulations of
galaxy cluster mergers: We present results from a suite of binary merging cluster simulations. The
hydrodynamical cluster simulations are performed employing a smoothed particle
hydrodynamics (SPH) formulation in which gradient errors are strongly r... | Cosmological parameters from weak cosmological lensing: In this manuscript of the habilitation \`a diriger des recherches (HDR), the
author presents some of his work over the last ten years. The main topic of
this thesis is cosmic shear, the distortion of images of distant galaxies due
to weak gravitational lensing by ... |
Inner Polar Rings and Disks: Observed Properties: A list of galaxies with inner regions revealing polar (or strongly inclined
to the main galactic plane) disks and rings is compiled from the literature
data. The list contains 47 galaxies of all morphological types, from E to Irr.
We consider the statistics of the param... | Ruling out the power-law form of the scalar primordial spectrum: Combining Planck CMB temperature [1] and BICEP2 B-mode polarization data
[2,3] we show qualitatively that, assuming inflationary consistency relation,
the power-law form of the scalar primordial spectrum is ruled out at more than
$3\sigma$ CL. This is an ... |
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